Miniature gasoline engine



, oct. 29, 1946. w I D. MILLER 2,410,229

MINIATURE GASOLINE ENGINE A Filed oct. 4, 1944 2 sheets-sheet 1 74 Y gl "1 l :l l 6 'as 447A@ 5 .4 Q8 48 70 69 Suventor g Anf/a /W/A fle.

attorney.

' Oct.v29, 1946. D. MILLER v MINIATURE GASOLINE ENGINE Filed ot. 4, 1944 2 sheets-sheet' Zsuentor:

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Patented Oct. 29,` 1946 UNITED STATES PATENT GFFICE Y 2,410,229 Y I MINIATURE GASOLINEENGINE Daniel Miner, Montebello, Calif. Application October 4, 194:4,v Serial No.y 557,133VV (Cl. 12s-59) 15 Claims. l

My invention relates tol miniature internal combustion motors, and relates in particular to a small gas engine especially suitable for powering model aircraft.

It is an object of my present invention to provide an improved and practical construction for miniature gasoline engines wherein the parts may be economically formed so as to cooperate upon assembly in a structure which will give good performance and durability such that its period of use without need for repairY or reconditioning will be extended.

It is an object of the invention to provide in this engine a simple crank case so formed that it maybe used in a one cylinder engine construction or in a two cylinder engine construction. This feature of the invention enables a purchaser of the one cylinder engine to later convert it to a two cylinder engine by obtaining additional parts, or, if the user has the complete set o-f parts, he may, as desired, have available either a one cylinder engine or a two cylinder engine, depending upon the manner in which he assembles the cooperating parts.

A further object ofy the invention is to provide a simple shaft and crank construction for a miniature internal combustionengine. The invention makes possible the use of connecting rods which are complete in one p iece forthe reason that in assembling the engine, it is not necessary to separate the bearing structure at the crank end of the connecting rod in order to place the bearing at the crank end of the connecting rod on the cooperating crank pin.

A further object is to provide an internal combustion engine having a pair of crank cases and a nozzle means for connecting these crank cases in side by side relation, the connecting means providing a bearing openingfor a crank shaft member having crank arms rigidly formed on the ends thereof for operative connection to crank pins which, when the engine parts are assembled, are disposed within the crank cases.

A further object of the invention is to provide in a miniature aircraft construction a simple arrangement whereby the fuel mixture is fed into the crank cases, from which it is conveyed to the cylinders.

A further object of the invention is to provide same. l

Further objects and advantages of the invention will be brought out in the following part of the specification.

longitudinal axis of the engine, as shown in Fig.

I a simple distributor and means for operating the Referring to the drawings which are for illustrative purposes only,

Fig. 1 is a plan View of my invention embodied in a single cylinder engine.

Fig. 2 is a view taken from the pos'tion indicated by the line 2-2 of Fig. 1. l

Fig. 3 is an enlarged fragmentary sectional view taken as indicated by the line 3-3 of Fig. 2.

Fig. 4 is an enlarged fragmentary section taken as indicated by the line 4-4 of Fig. 3.

Fig. 5 is a section taken as indicated by the line 5-5 of Fig. 3.

Fig. 6 is a section taken as indicated by the line 6-6 of Fig. 3.

Fig. 7 is a partly sectioned view showing my invention embodied in a two cylinder engine.

Fig. 8 is a fragmentary section taken as indicated by the line 8-8 of Fig. 7.

As shown in Figs. l to 6 inclusive, my invention includes a cylinder I0 comprising a shell I I which may be die cast from an aluminum alloy, this shell having thereina cylindric steel liner I2. The cylinder III has an exhaust port I3 on one side lthereof and an inlet port I4 on its opposite side, which communicates through a passage I5 with the interior of a crank case I6, in accordance with two cycle gas engine practice. '.The shell II includes circular ns Il around the upper portion thereof and parallel fins I8 projecting upwardly from the top wall I9 of the shell I I, these parallel fins being disposed in diagonal relation to the 1. Being thus disposed, the fins I8 are all in angular relation to 'the line or direction of movement ofthe engine when the aircraft is in flight so that the side walls of all of these ns I8 are brought into forceful contact with the air and an improved cooling result is attained for the head of the cylinder.

The crank ca se I6, which is secured to the lower end of the cylinder I0 by means of screws 20 defines a crank chamber 2|, surrounded by a circular wall 22. The front sideof the crank case I6 hasa large circular opening 23 therein and the rear side of the crank chamber 2| is closed by a wall 24, from which a distributor shaft support 25 projects, this distributor shaft support having an axial opening 26 which communicates with the crank chamber 2|. A crank shaft support 2I is bolted against the front of the crank case II by bolts 28 ina position to close the opening 23. The support 21 has a shaft opening 29, preferably lined with a steel or brass tube 30, to provide a bearing for the crank shaft 3|. 'I'he support `2'! is provided with a fuel inlet opening 32,

3 enclosed in part by an inlet tube 33. A gasoline inlet tube 34 extends diametrally across the tube 33 and has therein an orice 35, the now through which is controlled by a needle valve 36 which projects inward from a cap 31 threaded onto the projecting end 38 of the tube 34. The opposite end 39 of the tube 34 is adapted to be connected by means of a tube 4i), as shown in Fig. 4, to a gasoline supply, whereby the gasoline, under control of the needle valve 35, may be fed through the orice 35 into the air stream passing through the fuel inlet passage 32. tached to the cap 31 to rotate the same, whereby the position of the needle valve 3ft maybe adjusted.

A piston 42 is slidable in the cylinder IQ. This piston 42 has a pin 43 which passesthrough the opening 44 in the upper end of a connecting rod 45. The lower end of the connecting rod 45 projects, into the crank chamber 2i and has a continuous annular wall or Ihub'l defining a crank pin opening 4l for the lower end of the connecting rod 45. rEhe-rear end ofthe hub l has therein a circumferential groove' 48 providing an annular shoulder. l

The crank shaft 3i has on its inner'end a crank member 4S of such size that it may be moved through the op-ening 23 of the crank case l5 into the crank chamber 2l the crank mem-bel` 4S havinga crank pin which projects through the opening 4l at the lower end of the connecting rod 45. rIhe projecting end El of the crank shaft 3| has a squared portion 52 to receive a propeller mounting plate 53, and a threadedr portion 54 which projects through the propeller 55 and receivesl thereon a dome nut S, as shown in Fig. 7. The hub 5l of the plate 53 is formed so as to comprise a cam to actuate a breaker arm 58 which is mounted on a plate 5 9 having a hub 60 which is clamped around a projecting portion of the support 2l. For example, the hubl 60 may surround the projecting end or" the bearingsleeve "i6 ras shown in Fig. 7. Rotation lof the plate 59 on the 'axis ofthe shaft 3l provides adjustment for advancing or retarding the opening of the breaker points Si one of which is mounted on the arm 58 and the other of which is mounted on the plate 59. A. thrust bearing 62 is disposed between-the support 21 and the crank member 49.

A distributor shaft 63 extends through the shaft :g

opening 26. On the other end of this distributor A handle 4| is ateA shaft 63 there is a body of insulating material E4 and on the inner end of the shaft 63 there is a lever 65 constructed of thin metal and having at its end a fork E5 which straddles the rearwardly rotatable body 64; The case 68 consists of a cup having a shoulder 69 to engage the cylindrio wall l which projects rearward as a part of the crank case IE, and the cup 68 is `held in position by a pair of spring clipsfll, theoppositey ends of which engage openings l2 in thewall l0, 'and openings 'I3 in the cnd'of the case 68 near itsouter wall. In the center of the case 68 thereis a connector screw 14, the inner end of which engages a metal distributor' arm l5 which is mounted on the dis.- 'tributor body 64 so as to lextendaround one p'erpheral portion thereof. To cooperate with the member l5, the case 23 carries diametrally opn posed screws l to which high tension circuit wires may be connected, it bemg understood that for a single cylinder engine, only one of these screws 'I6 is employed for connection to the single spark plug TE, then used, both of the screws 16 being employed when the distributor cap is used in the two cylinder assembly, shown in Fig. 7.

* In the Jtwo cylinder arrangement shown in Fig.

7, the cylinder lo, crank case it, connecting rod ft', distributor shaft $3, lever t5, and distributor mechanism, including the case S8, are employed. Also, the shaft 3l is employed with the associated breaker point mechanism and propeller mounting means previously described. A second cylinder lll is provided, which is of the same form and construction as the cylinder lo. To this cylinder iii a crank case it" is attached, this crank case I6. having an opening 23 which faces andA is spaced from the opening 23 of the crank case '15. The crank case i6" has a shaft opening 29which is lined with the bearing sleeve 3U and the shaft Si is extended through the opening 3D so that its crank member 49 will lie within the crank chamber 2| ofthe crank case it and its crank pin 59 will pass through the crank pin opening 4l of a connecting rod 45 which extends from the crank chamber 2l into the cylinder iii' to engage the piston 42 therein. AThe crank cases land IS' are connected by a crank case'connecting member 'i8 having a shaft opening 'i9 aligned with the shaft opening 29 to receive the shaft portion 32) of a crank shaft member 8l which has on its leftward or front end a crank arm 82 and has on its rear end a crank member 83 which is similar to the crank Ymember 49 and `has -a crank pin 84 to project through the opening 4'! in the lower end of the connecting rod 45. The connecting meinber F8 is split longitudinally thereof so that the shaft portion 823 of the crankshaft member lli may be placed in the shaft opening '19, or, in other words, so that the connecting member i8 may be assembled aroundthe shaft portion Si, since the shaft portion 8l cannot be moved axially into and through the opening i9 due to the enlargement on its end. l n In accordance Vwith the foregoing, the connecting member 'i8 is separable on the plane A--A, Fig. 8, so that it consists of a section 85 and a section 3S arranged so that they will meet on the plane .l-A, and having cooperative laterally extending plate portionsl 8l' which meet on the plane A-,A and maybe connected together by screws 88. The connecting member 18 has flanges 89 at the ends thereof. to engage the crank cases l5 and I6 and close the openings .23 and v23 thereof when the crank cases Iii andlii Vare clamped against the ends of the connecting member'l by means ofbolts. j

The crank shaft member 8l has axial'openings 9i leading in from the opposite ends thereof to intake ports 92 which are faced laterally in oppo- ,site directions. The upper section v85 of the contheupper section 85, deiines an inlet chamber 95 which Acommunicates with thepassages 93, and

has an air inlet tube 96 leading thereinto, also a transverse gasoline inlettube 34' transversing the tube S6 in the manner describedwith 'relation to the gasoline inlet tube 34 of `Fig. Ll, and its relation to theair inlet tube 33, this gasoline inlet tube 34 having a needle valve 36 of the character shown in detail in Fig. 4.

The crank arm 82 of the crank sha-ft member 8l is provided with means whereby it may have operative connection With the crank pin 45', whereby rotation produced by the operation of the piston 42 in the cylinder I0 may be carried from the crank pin 84 through the crank pin 45 to the power output shaft 3| of Fig. '7, in' addition to the power which this output shaft 3| receives from the piston 42 operating in the cylinders I0. The crank arm 82 has means of coengagement with the crank member 49 represented by an opening 97 in the crank member 32, which receives the projecting end of the pin 5U.

The simple assembly shown in Fig. 7, accordingly, does not employ a continuous rigid crank shaft extended through the several crank chambers, but instead has a sectional crank shaft consistin'g of the crank shaft member 8! andthe output shaft 3! with detachable means of engagement between them, so that both of these parts 3l and Si act as a single unit when the simple engine structure is assembled in the inanner previously described. Furthermore, the arrangement shown does not require split bearings for the Yconnecting rods, but the connecting rod bearings are simply formed by' continuous, integral, annular walls at the ends of the connecting rods defining bearing openings through which the pins 43, 45', and 84 maybe passed, as a part of the assembly operation.

I claim as my invention:

l. In an internal combustion engine, the combination of: iirst and second body members in side by side relation, each consisting of a cylinder and a crank case; a piston in each of said cylin ders and a connecting rod extending from each piston into the cooperating crank case; an intercc-nnecting crank shaft member extending from one of said crank cases to the other, said crank shaft member having a shaft portion with a first crank arm at one end thereof in the crank case of said first body and a crank member at the other end thereof in the crank case of said second body member; interconnecting means to connect said crank cases together having a shaft opening to receive said shaft portion, said means having a removable part to expose said shaft opening to one side so that said shaft portion may be placed in said shaft opening from the side of said interconnecting means; an output shaft extending into the crank case of said first body member in alignment withsaid shaft portion, said output shaft having a second crank arm spaced from said first crank arm; crank pin means connecting said first and second crank arms, saidcrank pin means engaging one of said t vconnecting 'rods andV being disengageable 'from one of said crank arms; and crank pin'cmeans on said crank member engaging the connecting rod in the crank case of said second body member.

` 2; In an internal combustion engine, the com- Y interconnecting means to connectsaid vcrank cases together comprising members separable' along; a longitudinal plane, there being a longitudinal shaft opening between said separable members into which said shaft portion may be placedby lateral movement; an output shaft extendingv into the crank case of said'first body member Ain alignment with said shaft portion, said output shaft having a second crank arm spaced from said first crank arm; crank pin means connecting said first and second crank arms and one of said connecting rods and being disengageable'from one of said crank arms; and crankv pin means providing engagement'between said crank member and -the connecting rod in f the crank case of said second body member. l

shaft member having a shaft portion with a first.

crank arm at one end thereof in the case of '.said iirst'body member. and a crank member at the other end thereof in the case of said second body member; interconnecting means to connect said crank cases together comprising members separable along a longitudinal plane, therebeing a longitudinal shaft opening between said separable members into which said shaft portion may be placedY byv lateral movement; an output shaft extending into the crank case of said first body member in alignment with` said shaft portion, said output shaft having a second crank arm spaced from said first crank arm; crank pinv means connectingV said first and secondcrank arms and one of said connecting rods; and crank pin means providing engagement between said crank member and the connecting rod in the crank case of said second body member.

4. In aninternal combustion engine, the combination of: rst and second body members in side by side relation, each consisting of a cylinderl and a crank case, said crank cases having lateral openings faced toward each other; a pis-' ton in each of said cylinders and a connecting rod extending from each piston into the cooperatingl crank case; an interconnecting crank shaft member extending from one of said crank cases to the other, said crank shaft member. having a shaft portion with a rst crank arm at one'end thereof in the caseof said first body member and a crank member at the other end thereof in the case of said second body member; interconnecting means extending from onek of said lateral openings to the other to connect said crank cases together having a shaft opening to receive said shaftvportion, said means having a removable part to expose said shaft opening to one side soA thatsaid shaft portion may beiplaced in said shaft opening from the side of said interconnecting means; an output shaft extending into the crankv case of said first body member in alignment with said shaft portion, said output Vshaft having a second crank arm spaced 'from said first crank arm; crank pin means connecting said first and second crank arms and one of said connecting rods and being disengageable from one of said crank arms;l and crank pin means providing engagement between said crank member andthe connecting rod in the crank case of saidfsecond body member.

5. In an internal combustion engine, the combination of: rst and second body members in side by side relation, each consisting of a cylinder and a crank case, said crank cases having lateral openings faced toward each other; a piston in each of said cylinders and a connecting rod extending from each piston into the cooper-v an interconnecting crank.

ating crank case shaft member extending from one of said crank cases to the other, said crank shaft member having a shaft portion with a first crank arm at one end thereof inthe case of said first body member and a crank memberat the other end thereof inthe case of said second body member; interconnecting means extending from one of said lateral openings to the other to connect said crank cases together comprising members separable alongA a longitudinal plane, there being a longitudinal shaft opening between said separable members into which said shaft portion may be placed by lateral movement;` screw means to securesaid crank cases to the ends of saidV interconnecting.' means; an output shaft extending into the crank case of said first body member in alignment with said shaft portion, said output shaft having a second crank arm spaced from said first crank arm; crank pin means connecting said first and second crank arms and one of said connecting rods and being disengageable from one of said crankv arms; and crank pin means providing engagement between said crank member and the connecting rod inthe crankl case of saidsecond member.

6. In an internal combustion engine, the combination of: first and second body members in side by side relation, comprising a first crank case with a connected cylinder and a second crank case with a connected cylinder; a piston in each of said cylinders and connecting rods extending from said cylinders into said crank cases, said connecting rods having pin openings at the lower ends thereof; an interconnecting crank member havingrv a shaft portion extending from one of said crank cases to the other, said shaft portion having in said first crank case a crank arm withv a pin opening therein and having. in said second crank case a crank member having a crank` pin extending into the pin opening of the connecting rod whichI extends intovv said second crank case; interconnecting means to connect said crank cases together having a shaft opening to receive said shaft portion and a separate part extending from end to end thereof whereby saidy shaft opening may be exposed along one side so that said shaft portion may be placed therein; and an output shaft extending into said rst crank case in alignment with said shaft portion, said output shaft having a crank member in said first crankcase with a crank pin disposed so as to4 project through: the pin opening of. the connecting rodwhich extends into said first crank case and into the pin opening of said crank arm.

7. In an internal combustionengine, the combination. of: first and second body members in side byl side relation, comprising a. first crank casevvith afconnectedcylinder anda-second crank case with a connected cylinder;- a pistonin eachof said cylinders and connecting rods extending from said cylinders into said crank cases, said connecting rods'having pin openings at the lower ends thereof; an` interconnecting crank` member having a shaft portion extending from'one of said crank cases to the other, said shaft portion having insaid first crank case a crank. arm with a pin opening therein and having in said. second crank casea crank. member having a crank pin extending into the pin opening of the connecting rod which extends into said second crank case; interconnecting means to connect said crank cases together having a shaft opening to receive said shaft portion and a separable part extending from end to end thereof whereby said shaft opening may be exposed along one side so that said shaft portion may be placed therein; an output,

shaft extending into said first crank case in alignment with saidr shaft portion, said output shaft having a crank member in said first crank case with a crank pin disposed so as to project through the pin opening of the connecting rod whichv extends into said first crank case and into the pin opening of said crank arm; a distributor shaft extending into said second crank case in alignment with said shaft portion; a distributor operated by the outer end of said distributor shaft; and a lever on the inner end of said distributor shaft arranged to be driven by the rotation of the crank member in said second crank case.

8, In an internal combustion engine, the combination of: first and second body members in side by side relation, comprising a first crank case with a connected cylinder and a second crank case with a connected cylinder; a piston in each of said cylinders and connectingV rods extending from said cylinders into said crank cases, said connecting rods having pin openings at the lower ends thereof; an interconnecting crank member having a shaft portion extending from one of said crank casesto the other, said shaft portion having in said first crank case a crank arm witha pin opening therein and having in said second crank case a crank member having a crank pin extending into the pin opening; of the connecting rod which extends into said second crank case; interconnecting means to connect said crank cases together having a shaft opening to receive said shaft portion and a separable part extending from end to Vend thereof whereby said shaft opening may be exposed along one side so that said shaft portion may be placed therein; an output shaft extending into said first crank case in alignment with said shaft portion, said output shaft having a crank member in said first crank case with a crank pin' disposed so as to project through the pin opening of the connecting rod which extends into said first crank case and into the pin opening of said crank arm; a. distributor shaft extending into said second crank case in alignment with said shaft portion; a distributor operated by theouter endv of said distributor shaft; and a lever on the inner end of said distributor shaft having a fork engaging the hub of the connecting rod which extends into said second crank case soas to be rotated by the rotation of the crank member therein.

9. In an internal combustion engine, the combination of first and second body members in kside by side relation, comprising a first crank case with a connected cylinder and a second crank case with a connected cylinder; a piston.

in each of said cylinders and connecting rods extending from said cylinders into said crank cases, said connecting rods having pin openings at the lower ends thereof; an interconnecting crank member having a shaft portion extending from one of said crank cases to the other, said shafty portion having in said rst crank case a crank arm with a pin' opening therein and having insaidwsecond crank case a crank member having;

'9? a` crankA pin extending finto the pin openingfof the connecting `rod which extends into said second crank case; interconnecting means 'to 'connect said crank cases together, comprising a'rst-half vand a second half engaging on la median longitudinal plane and 'beingc'ooperatively cham- Abered sothat when they are placed ori-opposite sides of said shaft portion,`they will form around said shaft portion ashaft opening in which said shaft portion is supported, means connecting the A two halves :together/to" form" aiunit, land means Yforconnectingzthe ends of said interconnecting means to-said'crank case; and an output shaft extending into'said first crank-casein alignment with said "shaft portion,I saidoutput shaft having a crank member in said flrst-crankcjase with a crank pin disposed so as to project through the pin opening of the 'connecting rodwhich extends into said first crank-case and'into the pin opening of said crank arm.

'10. In an internal combustion engine v0f the character described, theV combinationof: a cylinder; a crank case `connected to the lower end of said cylinder, said crank case having a crank opening in the front wall thereof, and a distributor shaft opening in the rear wall thereof substantially aligned with said crank opening; a piston in said cylinder; a connecting rod extending from said piston into said crank case, said rod having a pin opening at its lower end and a hub projecting toward the rear wall of the crank case; a crank member of a size to pass from the exterior of said crank case through said crank opening into said crank case; a crank pin on said crank member extending through said opening of said rod; a shaft extending outward from said crank member; supporting means to support said shaft for rotation comprising a body having a wall to close said shaft opening and an opening through which said shaft may project into the exterior and providing bearing means to support said shaft; means to secure said supporting means to said crank case; a distributor shaft projecting through said shaft opening; and a lever on the inner end of said distributor shaft engaging said hub of said connecting rod so as to be rotated in response to rotation of said crank member.

11. In an internal combustion engine of the character described, the combination of a cylinder; a crank case connected to the lower end of said cylinder, said crank .case having a crank opening in the front Wall thereof, and a distributor shaft opening in the rear wall thereof substantially aligned with said crank opening; a piston in said cylinder; a connecting rod extending from said piston into said crank case, said rod having a pin opening at its lower end and a hub projecting toward .the rear Wall of the crank case, said hub having an annular groove therearound; a crank member of .a size to pass from the exterior of said crank case through said crank opening into said crank case; a crank pin on said crank member extending through said opening of said rod; a shaft extending outward from said crank member; supporting means to support said shaft for rotation comprising a body having a wall to close said shaft opening and an opening through which said shaft' may project into the exterior and providing bearing means to support said shaft; means to secure said supporting means to said crank case; a distributor shaft projecting through said shaft opening; and a lever on the inner end of said distributor shaft having a fork hub` so asl to be 'rotated' in response to rotation of said crankV member. y' `12. In an internal combustion bination of :v first vand second body members in side by siderelation, comprising a first crank case with a connected cylinder and a second crank rcase wi-thf'aconnectedcylind'em apiston in each Vof said cylinders and;connecting rods lextending from-saidicylin'ders into-rsai'dcra'n'k cases, said connectingrodshaving pin openings atthe lower ends thereof; faninterconnecting crank :member having 'a 'shaft portion'extendingvfrom one of said crank cases to theother, there being fuel passages extending into said shaft portion from the ends thereof? with portsat their inner ends faced later- 'ally' 'in'V opposite directions, said Ashaft portion v'having in saidfr'st crank case -a crankarm'with a pin opening therein' and having insaid second crank'case a crank member' having a crank pin extending into the pin opening of the connecting rod-Which extends into said second crank case; interconnecting meansl to connect said crank cases together 'having a shaftopening to receive said shaft portion and a separablep'art extending from end 'to end'thereof whereby said 'shaft opening may be exposed along one side so that said shaft portion may be placed therein, said interconnecting means having a fuel inlet port in the side wall thereof positioned so as to connect alternately with said ports of said shaft portion; a fuel and air mixing means connected to said fuel inlet port; and an output shaft extending into said first crank case in alignment with said shaft portion, said output shaft having a crank member in said rst crank case with a crank pin disposed so as to project through the pin opening of the connecting rod which extends into said rst crank case and into the pin opening of said crank arm.

13. In an internal combustion engine, the combination of: first and second body members in side by side relation, comprising a rst crank case with a connected cylinder and a second crank case with a connected cylinder; a piston in each of said cylinders and connecting rods extending from said cylinders into said crank cases; an interconnecting crank member having a shaft portion extending from one of said crank cases to the other, there being fuel passages extending 0 into said shaft portion from the ends thereof with ports at their inner ends faced laterally in opposite directions, said shaft portion having in said rst and second crank cases crank means engaging the lower ends of said connecting rods; in- 5 terconnecting means to connect said crank cases together having a shaft opening to receive said shaft portion and a separable part extending from end to end thereof whereby said shaft opening may be exposed along one side so that said shaft portion may be placed therein, said interconnecting means having a fuel inlet port in the side wall .thereof positioned so as to connect alternately with said ports of said shaft portion;

and an output Shaft extending into said firstV 5 crank case in alignment with said shaft portion, said output shaft having a crank member in said first crank case connected to one of the crank members of said interconnecting crank member.

14. In an internal combustion engine, the combination of: first and second body members in side by side relation, comprising a first crank case with a connected cylinder and a second crank case with a connected cylinder; a piston in each of said ycylinders and connecting rods ex- 5 tending from said cylinders into said crank cases,

engine, the coml 11 said connecting rods having ypin `openings .at 'the lower ends thereof; an interconnecting crank member having a shaft `por-tion Lextending from one of said crank cases yto the other, there being fuel passages extending into `said shaft por-tion from the ends thereof with ports at their inner 1ends faced laterally in opposite directions, said shaft portion having in said first and second :crank cases crank means `engaging the lopenings in the lower ends of .said .connecting.rods; interconnecting .mcansto'connect said -crank Acases '.toigether .having ya shaft opening extending .from

end to end thereof to receive :said shaft portion,

fsaid interconnecting means having va fuelY inlet pistons `operative in said cylinders, and lconnecting rods extending from ysaid pistons into said crank cases, the Vcombination :of: an interconnecting crankshaft ,member rhaving a shaft por- `tion extending from one yof lsaid crank casesxto the other, there `being crank means connected to the mshaft .member for operatingsaid connecting rods, tand-.there .beinglfuel passages extending into 'said shaft portion from the ends .thereof with ports'at'the inner ends of said passages communi- "eating with the side wall of said shaft portion; .interconnecting means to connect said crank cases together, havinga shaft opening .to vreceive said shaft portion and a Vseparablepart extending :from end to end thereof whereby said shaft opening may be exposed along one side so that lsaid shaft portion may be placed therein, said interconnecting means having a fuel intake port in the side -Wall thereof formed so as to connect a1- ternately with said ports Yof said vshaft portion; and an output shaft extending into said rst crank .case having means for operatively connecting it to said crankshaft member.

DANIEL MILLER. 

